A
firewall is a network security system which is used to protect
computers from several types of Internet attacks. In this article we
will learn about a firewall and its purpose.
A firewall can be a
software (computer program or application) or hardware (dedicated
computer that runs a firewall program) device that filters the network
traffic between your computer network or PC and the Internet. Firewall
protection is necessary for computing devices like computers which are
enabled with an Internet connection. Firewalls enhance the security
level of your computer network by providing detailed information about
the traffic patterns of the network. It is an important and
indispensable device that acts as a security gate between trusted
networks (internal network) and an untrusted network (Internet). Before
understanding the purpose of a firewall, let's get to know some of its
important attributes.
Attributes of a Firewall
All network communication passes through the firewall
Only authorized traffic is allowed by the firewall
A firewall has the capability to withstand Internet attacks
Why a Firewall is Deployed
Computers
have thousands of ports that can be accessed for various purposes. The
firewall of your computer closes these ports except for some specific
ports that need to be kept open. The firewall in your computer acts as
the first line of defense in preventing any type of hacking into your
network, because, any hacker who tries to penetrate into a computer
network will look for open ports that can be accessible. A firewall not
only keeps away certain data packets from the Internet, but also
performs the following functions.
☛ A firewall is used to keep
confidential and valuable information from slipping out unnoticed by the
organization. For example, FTP (File Transfer Protocol) traffic of an
organization's computer network is controlled by a firewall. This is
done to prevent users in the network from sending confidential files
intentionally or unintentionally to other parties.
☛ Firewall
filters are also used to prevent specific traffic from flowing into the
subnets of a network. This prevents users from sharing music, and
playing games on the network. This type of application is useful
especially in corporate sectors.
☛ Another important purpose of a
firewall is to modify the data packets that come across the firewall.
This process is called Network Address Translation (NAT). There is a
certain type of NAT called the basic NAT, in which the private IP
(Internet Protocol) addresses of a computer network are concealed behind
a single IP address. This process is termed as IP masquerading. This
helps users in a network which consists of systems without public
addressable IP numbers, to access the Internet.
☛ Accuracy of
data such as financial information, product specifications, prices of
the products etc., are very important for any business to grow. If such
information is modified by an external source, it may directly lead to
collapse of the particular business. Firewalls prevent unauthorized
modification of data on a website.
☛ If systems are not available
to users on a timely basis, it will lead to decrease in employee
productivity, loss of consumer confidence, and bad publicity. Firewalls
ensure system availability.
Today's firewall technology is very
sophisticated. Earlier, firewalls worked by filtering the network
traffic using the IP address, port number, and protocol, but today's
firewalls can filter data by identifying the message of the content
itself. With the help of a firewall, sensitive or inappropriate
information can be prevented from passing through the interface. A
firewall is a great asset to an organization and so it must be
configured properly
